The KRAS oncogene is a member of the Ras family of GTPases that are involved in numerous cellular signaling processes. K-Ras mutations are gain-of-function mutations that are present in up to 30% of all tumors, including as many as 90% of pancreatic cancers. Due to the clinical significance of this protein, many attempts have been made to develop Ras inhibitors, but such attempts have been mostly unsuccessful. This is largely due to the difficulty in outcompeting GTP for the K-Ras binding pocket in cells, and the lack of known allosteric regulatory sites.